Muhammad Rafique Asi

Residues of aflatoxin B1 in broiler meat: effect of age and dietary aflatoxin B1 levels.

This study describes the effect of dietary levels of aflatoxin B1 (AFB1) and age of the birds upon the residue level in liver and muscles of broiler chicks. In three different experiments broiler chicks of 7, 14 and 28 days of age were kept for 7 days on contaminated rations having 1600, 3200 and 6400 μg/kg AFB1. AFB1 residues were detected earlier in younger birds and those fed high AFB1 dietary levels. The highest residue levels in liver and muscles of young chicks fed 6400 μg/kg AFB1 was 6.97±0.08 and 3.27±0.05 ng/g, respectively. Maximum residue concentration was high in birds of young age and those kept on high AFB1 ration. After withdrawal of AF contaminated rations, residues clearance was slow and AFB1 was detectable in liver and muscles of birds for longer duration in younger birds and those fed high AFB1 dietary levels. AFB1 residues in poultry tissues may buildup to high levels in areas with no regulatory limits on AFB1 levels of poultry feed and may pose a risk to consumers health.

Assessment of aflatoxins, ochratoxin A and zearalenone in breakfast cereals

Aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEN) were analysed in 237 breakfast cereal samples collected from central areas of Punjab, Pakistan. According to the results, 41% of the samples were found contaminated with AFs, out of which 16% and 8% samples were found to be above the European Union (EU) maximum content for AFB1 and total AFs, respectively. About 48% samples were found contaminated with OTA and 30% samples were found to be above the EU maximum content. The results have shown that 53% samples of breakfast cereals were found contaminated with ZEN and 8% samples were found to be above the permissible limit of EU. The highest mean level of AFB1 and total AFs were found in semolina i.e. 3.60 and 4.55 μg/kg, respectively. Similarly, semolina was the highest contaminated breakfast cereal for OTA (3.90 μg/kg), while cornflakes (brand B) was found highest contaminated with ZEN (13.45 μg/kg).

Survey of aflatoxins in chillies from Pakistan produced in rural, semi-rural and urban environments

Chilli peppers from Pakistan are consumed locally and also exported. Their quality is compromised by aflatoxins (AF) contamination. AF in chillies from rural, semi-rural and urban areas of the Punjab region of Pakistan were determined. Twenty-three (52.3%), 22 (50%) and 29 (65.9%) samples from rural, semi-rural and urban areas respectively, contained levels of aflatoxins which exceeded the European Union limits of >5 µg kg−1 for AFB1 and >10 µg kg−1 for total AF that apply to spices. Mean values for AFB1 in ground samples were 23.8, 14.8 and 14.0 µg kg−1 for rural, semi-rural and urban areas, respectively. Mean total AF in ground samples were 27.7, 17.7 and 16.2 µg kg−1 from equivalent locations. Eleven (50%), 12 (54.5%) and 14 (63.6%) whole samples from rural, semi-rural and urban areas, respectively, contained total levels of AF that exceeded European Union limits. The data indicate that individual localities have particular problems. In conclusion, the concentrations were often greater than the statutory limits set by the European Union.

Quality index of oils extracted from γ-irradiated peanuts (Arachis hypogaea L.) of the golden and bari varieties

Two varieties of peanuts were irradiated to 4, 6 and 8 kGy with Co(60). Their proximate compositions remained unaffected, but microbes were eliminated completely after irradiation to 8 kGy. HPLC was used to study tocopherols of irradiated and unirradiated oil samples. There were dose-dependent differences in physico-chemical values between the control and irradiated samples. Significant changes in tocopherol concentrations and peroxide values in the oils were observed after irradiation to 8 kGy. Fatty acid compositions did not change significantly. The study has shown that irradiation is an effective tool in preservation of peanut oil.

Aflatoxin M1 contamination in cow and buffalo milk samples from the North West Frontier Province (NWFP) and Punjab provinces of Pakistan

A total of 178 milk samples (94 of buffalo and 84 of cow) were randomly taken from Punjab and the North West Frontier Province (NWFP) of Pakistan (n = 89 in each province) and analysed for the presence of aflatoxin M1 (AFM1) by HPLC-FLD. From Punjab about 46% of buffalos and 49% of cows milks were contaminated with AFM1 as compared with 52% and 51% for milk samples from NWFP, respectively. Overall, the mean AFM1 concentration was 0.046 µg kg−1 with a maximum of 0.350 µg kg−1. All samples complied with the Codex Alimentarius limit of 0.50 µg kg−1 for AFM1 in milk, but 16.3% of samples exceeded the European Union maximum level of 0.05 µg kg−1. Another set of 415 buffalos and cows milk samples (213 morning milks and 202 evening milks) were analysed. Statistical analysis revealed significant differences (p < 0.05) between mean AFM1 concentrations in milk during the morning (0.043 µg kg−1) and the evening (0.028 µg kg−1) lactation times.

The presence of aflatoxins and ochratoxin A in rice and rice products; and evaluation of dietary intake

In present study aflatoxins (AFs) and ochratoxin A (OTA) were analysed in 208 samples of rice and products collected from central areas of Punjab, Pakistan. The analysis was carried out using HPLC equipped with fluorescence detector. The results have shown that 35% of the samples were found contaminated with AFs, out of which 19% and 24% samples were found to be above the European Union (EU) maximum content for AFB1 and total AFs, respectively. About 19% samples were found contaminated with OTA and 14% samples were found to be above the EU maximum content. The highest mean level of AFB1 and total AFs were found in brown rice samples i.e. 8.91 and 12.4μg/kg, respectively. However, white rice samples have shown the highest mean level of OTA (8.50μg/kg) with highest level of 24.9μg/kg. The high mean dietary exposure 22.2 and 24.2ngkg(-1)bwday(-1) to AFB1 and OTA, respectively poses significant health hazard for local population.

Aflatoxin M1 in milk from urban and rural farmhouses of Punjab, Pakistan

Aflatoxin M1 (AFM1) was determined in 107 milk samples collected from urban and rural farmhouses from Punjab, Pakistan, by HPLC with fluorescence detection. An incidence rate of 64% (38/59) in milk samples from urban farmhouses was found, with a mean concentration of 0.064 ± 0.023 μg L−1. In rural samples about 52% (25/48) of milk samples were contaminated with AFM1, with a mean of 0.04 ± 0.034 μg L−1. About 42% of milk samples from urban and 27% from rural farmhouses were well above the limit permitted by the European Union (EU). However, only 15% and 8% of milk samples from urban and rural farmhouses, respectively, exceeded the limit of USDA/Codex regulations. The results showed that the contamination of milk with AFM1 from Punjab, Pakistan, when compared with Codex limit is present and needs continuous monitoring. The awareness and education among dairy farmers on the potential health risks associated with aflatoxins should be communicated.

Assessment of hot peppers for aflatoxin and mold proliferation during storage.

Aflatoxin contamination and mold proliferation in three hot pepper hybrids (Sky Red, Maha, and Wonder King) were studied during 5 months of storage at three temperatures (20, 25, and 30°C) and under different packaging conditions (low-density polyethylene bags and jute bags). The presence of aflatoxins in hot pepper samples was determined by high-performance liquid chromatography with a UV-Vis detector. Sampling for analysis of aflatoxins, total mold counts, and Aspergillus counts was carried out at 0, 50, 100, and 150 days of storage. Hot peppers packed in jute bags were more susceptible to aflatoxin contamination than those packed in polyethylene bags; aflatoxin concentrations were 75% higher in peppers stored in jute bags. The effect of storage temperature resulted in aflatoxin concentrations that were 61% higher in hot peppers stored at 25 and 30°C than in those stored at 20°C. Of the three pepper hybrids, Wonder King was more susceptible to aflatoxin contamination, with a maximum of 1.50 μg/kg when packed in jute bags and stored at 25°C for 150 days. However, no sample exceeded the maximum permitted level for total aflatoxins in spices established by European Union regulations (10 μg/kg). Total mold counts and Aspergillus counts increased with storage duration, but all counts were significantly lower in peppers stored in polyethylene bags. A gradual increase in temperature during prolonged storage of hot peppers in combination with aeration may be the main reasons for increases in fungal biomass and Aspergillus proliferation with the subsequent aflatoxin production.

Mold and aflatoxin reduction by gamma radiation of packed hot peppers and their evolution during storage.

The effect of gamma radiation on moisture content, total mold counts, Aspergillus counts, and aflatoxins of three hot pepper hybrids (Sky Red, Maha, and Wonder King) was investigated. Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and stored at 25°C for 90 days. Gamma radiation proved to be effective in reducing total mold and Aspergillus counts in a dose-dependent relationship. Total mold counts in irradiated peppers immediately after treatments were significantly lowered compared with those in nonirradiated samples, achieving 90 and 99% reduction at 2- and 4-kGy doses, respectively. Aspergillus counts were significantly reduced, by 93 and 97%, immediately after irradiation at doses of 2 and 4 kGy, respectively. A radiation dose of 6 kGy completely eliminated the population of total molds and Aspergillus fungi. The evolution of total molds in control and irradiated samples indicated no further fungal proliferation during 3 months of storage at 25°C. Aflatoxin levels were slightly affected by radiation doses of 2 and 4 kGy and showed a nonsignificant reduction of 6% at the highest radiation dose of 6 kGy. The distinct effectiveness of gamma radiation in molds and aflatoxins can be explained by the target theory of food irradiation, which states that the likelihood of a microorganism or a molecule being inactivated by gamma rays increases as its size increases.

Determination of organochlorine and nitrogen containing pesticide residues in Labeo rohita

Two different weight groups of farmed Labeo rohita were collected from fish hatchery, Satiana Road Faisalabad, Pakistan. Pesticide residues were determined by high-performance liquid chromatography (HPLC). HPLC analysis showed that seven pesticide residues (α-endosulfan, DDE, parathion methyl, isoproturon, atrazine, carbofuran, and deltamethrin) were detected in L. rohita in weight group W 1.Six pesticide residues (α-endosulfan, parathion methyl, isoproturon, atrazine, carbaryl, and carbofuran) were found in L. rohita weight group W 2. The overall comparison between two weight groups of L. rohita showed that maximal concentration of pesticide residues were observed in underweight group W 2 compared to W 1 weight group.